Let a planetary system be solely consisted of the earth and the sun with the earth revolving around the sun in a perfectly circular orbit. If the radial distance (R) of the earth from the sun is doubled, what will be the new revolving time (T)? If I apply Kepler's law of $T^2$ proportional to $R^3$ that yields T=1032 days. However, if I apply the conservation law of angular momentum:
Mass(m)$\times$angular speed(w)$\times$$R^2$= Constant,
or (2$\times$$\frac \pi T$)$\times$$R^2$=constant,
or T proportional to $R^2$; that is different from the Kepler's law! Can you please tell me in which assumption I am making the mistake?